Whoa there, slow down. First of all, what made you go buy the EQ in the first place? My guess it was for additional control over the sound of your bass. If that's the case, option 2 and leave one side of your EQ unused. Having the EQ in-line means that it is by default also acting to shape the tone of whatever goes through your effects loop, so EQing it again shouldn't be necessary.

Gig it like that for a while and wait and see if a use for the spare EQ becomes apparent.

IMO as soon as you start EQing effects loops or DI sends, you're only adding complication for lot a lot of benefit.

Yeah, I bought it because I want to be able to tweak my sound more. The Demeter pre, however good it does sound, does leave a bit to be desired when it comes to more than 3-band EQ'ing.
Plus with my Spector being so damn trebly, I want to be able to tackle that obstacle as well.